#include <stdio.h>
#include <stdlib.h>
#include <string.h>

unsigned char *g_pkt_buffer = NULL;
unsigned int   max_pkt_size = 0;
FILE *fpout = NULL;
#define READIO_HDR_SIZE     26
#define IEEE80211_ADDR_LEN 6

#define IEEE80211_FC0_VERSION_MASK      0x03
#define IEEE80211_FC0_VERSION_SHIFT     0
#define IEEE80211_FC0_VERSION_0         0x00
#define IEEE80211_FC0_TYPE_MASK         0x0c
#define IEEE80211_FC0_TYPE_SHIFT        2
#define IEEE80211_FC0_TYPE_MGT          0x00
#define IEEE80211_FC0_TYPE_CTL          0x04
#define IEEE80211_FC0_TYPE_DATA         0x08

#define IEEE80211_FC0_SUBTYPE_MASK      0xf0
#define IEEE80211_FC0_SUBTYPE_SHIFT     4
/* for TYPE_MGT */
#define IEEE80211_FC0_SUBTYPE_ASSOC_REQ     0x00
#define IEEE80211_FC0_SUBTYPE_ASSOC_RESP    0x10
#define IEEE80211_FC0_SUBTYPE_REASSOC_REQ   0x20
#define IEEE80211_FC0_SUBTYPE_REASSOC_RESP  0x30
#define IEEE80211_FC0_SUBTYPE_PROBE_REQ     0x40
#define IEEE80211_FC0_SUBTYPE_PROBE_RESP    0x50
#define IEEE80211_FC0_SUBTYPE_BEACON        0x80
#define IEEE80211_FC0_SUBTYPE_ATIM          0x90
#define IEEE80211_FC0_SUBTYPE_DISASSOC      0xa0
#define IEEE80211_FC0_SUBTYPE_AUTH          0xb0
#define IEEE80211_FC0_SUBTYPE_DEAUTH        0xc0
#define IEEE80211_FCO_SUBTYPE_ACTION        0xd0
/* for TYPE_CTL */
#define IEEE80211_FC0_SUBTYPE_PS_POLL       0xa0
#define IEEE80211_FC0_SUBTYPE_RTS       0xb0
#define IEEE80211_FC0_SUBTYPE_CTS       0xc0
#define IEEE80211_FC0_SUBTYPE_ACK       0xd0
#define IEEE80211_FC0_SUBTYPE_CF_END        0xe0
#define IEEE80211_FC0_SUBTYPE_CF_END_ACK    0xf0
/* for TYPE_DATA (bit combination) */
#define IEEE80211_FC0_SUBTYPE_DATA      0x00
#define IEEE80211_FC0_SUBTYPE_CF_ACK        0x10
#define IEEE80211_FC0_SUBTYPE_CF_POLL       0x20
#define IEEE80211_FC0_SUBTYPE_CF_ACPL       0x30
#define IEEE80211_FC0_SUBTYPE_NODATA        0x40
#define IEEE80211_FC0_SUBTYPE_CFACK     0x50
#define IEEE80211_FC0_SUBTYPE_CFPOLL        0x60
#define IEEE80211_FC0_SUBTYPE_CF_ACK_CF_ACK 0x70
#define IEEE80211_FC0_SUBTYPE_QOS       0x80
#define IEEE80211_FC0_SUBTYPE_QOS_NULL      0xc0

#define IEEE80211_FC1_DIR_MASK          0x03
#define IEEE80211_FC1_DIR_NODS          0x00    /* STA->STA */
#define IEEE80211_FC1_DIR_TODS          0x01    /* STA->AP  */
#define IEEE80211_FC1_DIR_FROMDS        0x02    /* AP ->STA */
#define IEEE80211_FC1_DIR_DSTODS        0x03    /* AP ->AP  */

#define IEEE80211_FC1_MORE_FRAG         0x04
#define IEEE80211_FC1_RETRY             0x08
#define IEEE80211_FC1_PWR_MGT           0x10
#define IEEE80211_FC1_MORE_DATA         0x20
#define IEEE80211_FC1_WEP               0x40
#define IEEE80211_FC1_ORDER             0x80


#define NULL_DATA_FLAGS (IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA | IEEE80211_FC0_SUBTYPE_NODATA)
#pragma pack(1)
struct pcap_timeval {
    unsigned int    GMTtime;
    unsigned int    microTime;
};

struct ieee80211_frame {
    unsigned char i_fc[2];
    unsigned char i_dur[2];
    unsigned char i_addr1[IEEE80211_ADDR_LEN];
    unsigned char i_addr2[IEEE80211_ADDR_LEN];
    unsigned char i_addr3[IEEE80211_ADDR_LEN];
    unsigned char i_seq[2];
};

struct pcap_file_header {
    unsigned int magic;
    unsigned short version_major;
    unsigned short version_minor;
    unsigned int thiszone;
    unsigned int sigfigs;
    unsigned int snaplen;
    unsigned int linktype;
};

struct pcap_pkthdr {
    struct pcap_timeval  ts;
    unsigned int    caplen;
    unsigned int    len;
};

int check_file(FILE *pfile)
{
    struct pcap_file_header file_header;
    size_t read_size = 0;

    if ((read_size = fread(&file_header, 1, sizeof(file_header), pfile)) != sizeof(file_header)) {
        return -1;
    }

    if (file_header.magic != 0xa1b2c3d4
        || file_header.version_major != 2
        || file_header.version_minor != 4) {
        return -1;
    }

    if (file_header.linktype != 105
        && file_header.linktype != 127) {
        return -1;
    }

    return 0;
}

int get_next_pkt(FILE *pfile, unsigned char **pkt_buf, unsigned int *pkt_size)
{
    struct pcap_pkthdr pkt_hdr;

    if (fread(&pkt_hdr, 1, sizeof(struct pcap_pkthdr), pfile) != sizeof(struct pcap_pkthdr)) {
        if (feof(pfile))
            return -1;
        printf("%s:read pkt_hdr error\n", __FUNCTION__);
        return -1;
    }
  
    if (pkt_hdr.caplen > max_pkt_size) {
        if (*pkt_buf != NULL) { 
            free(*pkt_buf);
            *pkt_buf = NULL;
        }

        max_pkt_size = pkt_hdr.caplen;
        *pkt_buf = malloc(max_pkt_size);
        if (*pkt_buf == NULL) {
            printf("%s:malloc error\n", __FUNCTION__);
            return -1;
        }
    }
    
    if (fread(*pkt_buf, 1, pkt_hdr.caplen, pfile) != pkt_hdr.caplen) {
        printf("%s:read packet data error!\n", __FUNCTION__);
        return -1;
    } 

    *pkt_size = pkt_hdr.caplen;
    return 0;
}


const unsigned int crc32_tab[] = {
      0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
      0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
      0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
      0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
      0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
      0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
      0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
      0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
      0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
      0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
      0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
      0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
      0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
      0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
      0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
      0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
      0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
      0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
      0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
      0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
      0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
      0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
      0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
      0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
      0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
      0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
      0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
      0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
      0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
      0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
      0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
      0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
      0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
      0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
      0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
      0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
      0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
      0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
      0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
      0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
      0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
      0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
      0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
      0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
      0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
      0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
      0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
      0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
      0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
      0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
      0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
      0x2d02ef8dL
};

/* This is the standard Gary S. Brown's 32 bit CRC algorithm, but
   accumulate the CRC into the result of a previous CRC. */
unsigned int
pcap_calc_crc32(unsigned int crc32val, unsigned char *s, unsigned int len)
{
    unsigned int i;

    if (s == 0) return 0L;

    crc32val = crc32val ^ 0xffffffff;
    for (i = 0;  i < len;  i++) {
        crc32val = crc32_tab[(crc32val ^ s[i]) & 0xff] ^ (crc32val >> 8);
    }

    return crc32val ^ 0xffffffff;
}

int pcap_for_each_frame(FILE *pfile, int (*fn_cb)(unsigned int no, unsigned char *buffer, unsigned int size))
{
    unsigned int        pkt_size;
    unsigned char *     pkt_buf = NULL;
	unsigned int		no = 1;

    while (get_next_pkt(pfile, &pkt_buf, &pkt_size) == 0) {
        fn_cb(no++, pkt_buf, pkt_size);
    }

    if (pkt_buf != NULL) {
        free(pkt_buf);
        pkt_buf == NULL;
    }

    return 0;
}

FILE *pcap_open(char *filename)
{
    unsigned int max_pkt_size = 0;
    FILE *pfile = NULL;

    pfile = fopen(filename, "r");
    if (pfile == NULL) {
        return NULL;
    }

    if (check_file(pfile) != 0) {
        return NULL;
    }

    return pfile;
}

void pcap_close(FILE *pfile)
{
    fclose(pfile);
}
